The most interesting rookie you need to know more about

"I haven't seen a ball [hit] like that," said Padres first baseman Eric Hosmer after San Diego beat Arizona, 4-1, on Friday. If you weren't watching the game, you couldn't possibly have imagined who he'd been talking about.
Remember, Hosmer spent years in Kansas City with powerful hitters like Mike Moustakas and Salvador Perez. He's shared a division with Miguel Cabrera and José Abreu, and a league with Mike Trout and Nelson Cruz. And Hosmer is teammates now with Wil Myers, and Paul Goldschmidt was in the D-backs' lineup that night. Hosmer has seen his share of sluggers who can crush baseballs.
The veteran first baseman wasn't talking about any of them. He was talking about relatively unknown rookie -- San Diego outfielder Franchy Cordero -- who in his 39th career game had crushed a 489-foot blast, the longest home run tracked by Statcast™ in 2018, and the ninth longest since the system came online in '15. For those who follow such things, it was the latest exhibition of Cordero's elite tools in his brief career. For everyone else, let's introduce you to the most interesting player you don't know enough about.

There's a difference between being exciting and being good, of course, and for the moment, Cordero is more the former than the latter. In 145 career plate appearances, his line of .237/.280/.467 outlines serious issues in getting on base. Cordero has struck out in 41 percent of his plate appearances, and in the history of baseball, there's never been a hitter to have a season of at least 400 plate appearances while striking out that much. Even in the strikeout-happy world of 2018, there's such a thing as too many strikeouts.
But we'll get back to that part, because Cordero is only 23, and 145 career plate appearances is only a handful more than guys like Trout and George Springer have piled up in the first few weeks of this season alone. Let's focus on the tools. The tools are loud.
Almost no one hits the ball harder
Hitting the ball hard is a skill. We've always known that, but it's a lot easier to quantify it now. When Cordero hit his monster home run vs. Arizona, it left the bat at 116.3 mph, making it the hardest-hit ball hit by a Padre since Statcast™ came online in 2015. The record stood for eactly three days, until he broke it on Monday night with a 116.5 mph liner in Colorado. He hit four balls in the 16-5 rout of the Rockies, and they were all crushed: 115.5 mph (lineout), 113.7 mph (home run), 105.6 mph (grounder), 104.0 mph (single). He's one of the very few players this year to have four balls hit 100 mph or more.

Now, he has the top three, four of the top five, and five of the top seven hardest-hit Padre balls since 2015, all in the past two weeks. Remember, Cordero has had 145 career plate appearances, and he's failed to make contact at all in nearly half of them -- yet he already owns the top of San Diego's leaderboard. 
Now, maybe that says more about the Padres than it does Cordero. Let's expand. Nearly 900 hitters have stepped to the plate in 2018. Only 17, or just over one percent, have hit a ball 115 mph. Only four have done it at least three times, and the other three hitters are probably exactly the three you would have guessed: Giancarlo Stanton, Aaron Judge and Joey Gallo. Cordero's there, too. You can't fake this.

We got a taste of this last year.In only 99 plate appearances. Cordero had 49 tracked balls in play, and five of them were hit at least 110 mph. That's as many as Kris Bryant had in 665 times to the plate. It's more than Cody Bellinger (three in 548 plate appearances), Corey Seager (two in 613 plate appearances) or Joey Votto (one in 707 plate appearances). It's not something Billy Hamilton has done even once in over 1,600 plate appearances since 2015.
There's more to life than exit velocity, of course. But there's a leaderboard with Stanton, Cordero, Judge and Gallo. This is a skill, and Cordero has it.
Elite speed with the best in the game
The other names on that exit velocity lists are good athletes, of course, but none of them are known for their speed. Cordero, meanwhile, had the most triples of anyone in the Minors in 2016, with 16, and the most triples of anyone in the Minors in 2017, with 18. (He'd add three more with the Padres.) Throw in six seasons of double-digit steals, and you figure he can move.

Cordero can, of course, and this is another thing that we can do a better job of explaining now. We measure speed with a metric called "Sprint Speed," which is expressed in feet per second on a player's competitive runs. (Read more about how it works here.) The Major League average is 27 feet per second, and the truly elite players can get over 30 feet per second.
Last year, there were 548 qualified players. Cordero's Sprint Speed was 29.8 feet per second, making him easily the fastest player on the Padres and placing him 15th overall -- or in the top three percent. This year, he's in the top 10 of 324 qualifiers, or, again, in the top three percent. That's elite, game-changing speed. The triples say it, the eye test says it, and the data does, too.
Quality defense despite inexperience
There was a time where Cordero was among the worst defenders in the Minors. Signed as an infielder, he made 44 errors in 56 games at shortstop in 2012; two years later, he made 51 miscues in 56 games. The next year, Cordero began his transition to left field, and he first became a full-time center fielder in '16.
That means that when Cordero made his Major League debut last year, he had barely more than a year of center-field experience under his belt. In a relatively small sample size… he was spectacular.
The way we explain that is relatively simple; by looking at the difficulty of every batted ball hit to an outfielder, we can see how many chances an average outfielder would have been expected to make, and how many the fielder in question actually converted. By looking at the difference between the two numbers, we can get to value added… or not.
In 2017, there were 180 outfielders with at least 40 catchable opportunities. Guess who added the most value.
Catch percentage added, 2017
+11 points, Cordero (84 percent expected catches, 95 percent made)
+7 points, Byron Buxton (87 / 94)
+7 points, Adam Engel (86, 83)
+6 points, Kevin Kiermaier (89, 95)
+6 points, Zack Granite (87, 93)
+6 points, Leonys Martin (88, 94)
Buxton and Kiermaier are almost universally considered the two best defensive outfielders in the sport, so that's a nice list to be on -- with the obvious caveat that Cordero didn't play anywhere near as often as they did.
Still, that kind of speed makes tracking down balls a little easier, and we saw what he could do when he turned this 39 percent Catch Probability play off the bat of José Peraza into an out:

… as well as going 97 feet to make this nice running play to rob Travis Shaw.

Of course, Cordero's misplay in the same Arizona game may have cost Tyson Ross a chance at a no-hitter.
Ultimately, we don't know what Cordero will turn out to be. It's worth noting we had a lot of the same conversations after 2016 about Milwaukee's Keon Broxton -- strong defense, great exit velocity and a concern about strikeouts -- and after a disappointing '17, he's back in the Minors. On the other hand, Judge came up and struck out 44 percent of the time in a partial season in '16, before breaking out last year.
Cordero is at least showing small signs of improving his plate discipline, cutting his swing rate as time goes on.

Cordero is still striking out too much -- 32.6 percent of the time in 2018. But in today's game, all you really need to do is get below 30 percent, if you have enough other tools, and he surely has that. (His lopsided .256/.289/.558 line is above average, thanks to that power.)
It's possible that like Broxton, Cordero might never make enough contact to let everything else shine. He might be nothing but unrealized potential. Cordero is not a star -- not now, maybe not ever. He's exciting, however. He's interesting. Cordero has all the physical talent you could want, and he's only 23, capable of playing a strong center field, showing elite speed and next-level power. On a rebuilding Padres team with plenty of young talent on the way, Cordero might be the most fascinating name of all.
This article was originally published on April 22 and the numbers were updated on April 24.